For 17 years, McNab piloted the Friends of Scottish Rugby – a group of primarily ex-pat Scots based in London – in their unstinting support of grassroots rugby in Scotland and to the Academy at London Scottish.

Four years ago, at a gala dinner graced by the Princess Royal and held in his honour in London, McNab was much tickled that as he became the organisation’s honorary life president, five people were taking over the duties that he had delivered single-handedly and in some inimitable style.

Born in 1933 in Charlton, near Greenwich, McNab was educated at Fettes College in Edinburgh and served as a second Lieutenant in the second Battalion, The Black Watch, during the Korean War.

He was wounded during that campaign – a bullet skipping near the top of his head and ending up with shrapnel in his hand!

He became a captain in the Royal Marines Volunteer Reserves in 1956 and had his own business intelligence service, while he always managed to change the subject if he was asked if he had been in the employ of the British Secret Service!

When he stepped down from an active role with Friends of Scottish Rugby, McNab thanked members for their support.

He wrote: “From the 34 junior Scottish rugby clubs and the London Scottish Academy; to donating funds to worthy causes which in themselves were not entirely rugby-orientated yet were deeply Scottish centred. From the Dunblane school massacre, to the Solway Harvester fishing boat disaster; to Erskine Home for wounded Scottish soldiers, you happily made generous donations.”

McNab was diagnosed with pancreatic cancer last year and was not expected to survive beyond Christmas 2019.

But his characteristic zest for life and rugby took considerably longer to subdue, making his way down from his bed as recently as the Autumn Nations Cup matches reached their climax earlier this month, to watch the action on TV.

David Mackay, President of Friends of Scottish Rugby, said: “Donald was a truly remarkable man.This is the passing of a legend.”

Scottish Rugby sends its sincere condolences to Donald’s family and many friends both here in the UK and in New Zealand.

Picture shows Donald McNab with HRH The Princess Royal.